Field of the Invention
This invention relates to lighting and lighting fixtures and, in particular, to apparatus, systems, and methods of aiming individually adjustable light modules that are mountable collectively into a lighting fixture.
State of the Art
In many lighting applications particular illumination criteria are specified or desired. An example is wide area lighting. Intensity, uniformity, and minimums across a target area are examples. Part of the job of a lighting designer is to select fixtures which meet those illumination specifications.
But a subtle aspect of fixture selection is not only what type of light output they create (e.g. light distribution pattern), but also how that output meets the lighting specifications when the fixture is aimed from its operating position to the target.
One older approach is to place fixtures in operating position relative the target area, manually aim them in some organized fashion, and test if the specifications are met. This, however, can be extremely resource and time intensive. For large or wide area lighting, this can mean elevating workers sometimes up to one hundred or more feet in the air, manually manipulating relatively large fixtures, and somehow communicating with workers down at the target if the aimings are right and if they meet requirements. Consider this for sports lighting having four tall poles, each with eight lighting fixtures. Just moving the elevated worker from pole to pole involves a large crane and significant time. Then to manually aim each fixture is resource intensive. It also involves human error in aiming.
More recently attempts have been made to use computerized programs to assist in selection of the fixtures and output patterns to effectively illumination a target, and to calculate how each will be aimed relative to the target area when in operating position. The programming can be translated to a factory-aiming methodology that allows each fixture to be pre-aimed (sometimes called factory aiming) on support structures (e.g. cross-arms). The pre-aimed fixtures/cross arms can then be taken to the actual target area and elevated into operating position. By, for example, confirming the cross arms or at least one fixture is correctly aimed to the target, the assumption is all fixtures are likewise. This can save considerable time and expense in the final installation of the lighting system.
U.S. Pat. No. 8,300,219, incorporated by reference herein and commonly owned by the assignee of the present application, describes and illustrates one such pre-aiming system related to high intensity, wide-area lighting fixtures having a single, large, high intensity discharge (HID) lamp per fixture. Machine vision and computer displays inform the worker how to aim the mounting elbow for each fixture to a cross arm in the factory. The cross arms are taken to the target, the lamp and reflector and other needed components assembled thereto, and the cross arms/fixtures raised on poles into operating position. U.S. Pat. No. 8,300,219 describes how such factory aiming of single-lamp fixtures can significantly save time and resources, and improve accuracy of aiming for such fixtures.
Even more recently, light emitting diode (LED) lighting has emerged as a viable substitute for HID lighting in wide or large area lighting, including but not limited to such things as sports lighting, roadway lighting, parking lot lighting, and the analogous illumination tasks. However, the size and light output of individual LEDs is a fraction of that of most wide area HID lamps. As of yet, quite a large number of LEDs must be mounted into a single fixture to achieve the light output and beam pattern distributions of typical HID fixtures. One approach is to mount the LEDs on a single mounting board inside a single large reflector to support and guide the light output. Sometimes individual optical components are placed over the LEDs to alter their beam patterns.
Another approach is to mount the many LEDs into the fixture but with structure that allows individual LEDs to be independently adjusted in at least one direction. The lighting designer can then have a highly customizable fixture in the sense that a large number of light output patterns from the single fixture can be created by the selection of the aiming direction of each LED in the fixture. An example is commonly owned U.S. patent application Ser. No. 13/399,291, incorporated by reference herein.
However, in a way this re-creates the older problem discussed above with regard to aiming fixtures. Each of the plural LEDs in the fixture must somehow be accurately aimed to achieve the designer's intended light output from the fixture when in operating position. As will be further discussed, some of these LED-based fixtures can have tens of LEDs. One example would be in a range of 50 to 100. To individually manually aim each one at the target site with the fixture elevated in operating position would add to rather than relieve the time and resource burden of on-site aiming discussed above.
In addition, the relatively small size of current individual LED assemblies, even with attendant optics (e.g. lens, reflectors, visors, etc.) does not lend itself to the computer vision jigs and system of U.S. Pat. No. 8,300,219, which is incorporated herein by reference. The issues this creates can be further appreciated by reference to a particular type of LED assembly discussed below.
LED (light emitting diode) modules such as those described U.S. patent application Ser. No. 13/399,291, which is incorporated by reference in its entirety, need to be aimed as discussed in Procedure 3000, step 3004 of FIG. 13 of said application, which is also reproduced as FIG. 11 of this application. Such lighting modules 10 are illustrated in FIGS. 3-7. A housing 60 (bowl-shaped shell) and mounting structure to mount modules 10 in housing 60 is shown in FIGS. 1-10, The independent aiming of each module 10 (which includes one or just a few LEDs 201) is required to produce a collectively light output distribution pattern from the single fixture on which they are mounted to be useful in meeting an illumination scheme designed or specified for a target area.
The following paragraphs from the aforementioned patent application explain the need and desirability of an improved aiming method.
The mechanics of aiming a module 10 have already been discussed, but to do so in a rapid and repeatable manner it is beneficial if all modules associated with an individual beam pattern are aligned to a common reference—readily visible to an assembler—while affixed to module bar 50, but prior to module bar 50 being installed in fixture housing 60. U.S. Pat. No. 8,300,219, discusses methods of aiming a plurality of objects to a common reference, though other methods are possible, and envisioned. In practice, each individual module could have a laser mounted thereon and the module pivoted until the beam projected from the mounted laser matched the position of an aiming point projected onto a wall or floor. This same approach could be applied to a module bar (e.g. see module bar or rail 50 in FIGS. 6, 7 and 10) in that the laser could be mounted to the bar and aimed to a reference point and the aiming of each LED module mounted to said module bar assumed to be accurate once the bar is aimed. The aiming of the fixture housing could be assured using the same method. Of course, a laser need not be used; a sensor/receiver setup could be used. There are a variety of methods by which LED modules 10 may be precisely aimed and though it is perhaps the easiest to aim LED modules 10 prior to installation in fixture housing 60, it is not a departure from aspects of the present invention to aim modules in situ.
Once a module bar/LED module assembly is fully built and aimed, it may be installed in fixture housing 60 according to step 3005 of method 3000 (FIG. 11). Ideally, no additional aiming or modification to the assembly is required once affixed to the interior of housing 60. The process is repeated according to step 3006 for all modules in a given fixture, after which outer components (see FIG. 2) are affixed according to step 3007 so to produce exemplary fixture 5000.
The foregoing illustrates some of the issues and difficulties that exist in the art. Although projecting a laser temporarily mounted on a module 10 when in place in a fixture housing 60 allows a worker to see a projection of the aiming direction of the module 10 relative to the surface and relative to housing 60, it is apparent that there is room for improvement in the art. There is a need for an improved way to translate the aiming orientation of each of the plural modules in an accurate and repeatable way relative to the designer's output distribution pattern needed from the fixture for each different lighting application. There is a need for highly flexible yet precise and accurate pre-aiming of such many relatively small, independently adjustable lighting modules for not only each fixture but for multiple fixtures, including when the aiming plan for modules differs from fixture to fixture. There is a need for improvement in technique, space requirements, automation, and processing of such pre-aiming projects.